1040922-83-5Relevant academic research and scientific papers
Process for the enantioselective preparation of pregabalin
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Page/Page column 14, (2009/02/10)
The invention provides a new enantioselective process for the preparation of (S)-pregabalin, or a pharmaceutical acceptable addition acid salt comprising: acid hydrolysis of the dioxolan ring of a chiral compound of general formula (I) to obtain compound
First stereoselective synthesis and assignment of the absolute configuration of the nebracetam eutomer and derivatives
Lima, Evanoel C.,Domingos, Jorge L.O.,Dias, Ayres G.,Costa, Paulo R.R.
, p. 1161 - 1165 (2008/09/20)
(-)-Nebracetam 1 was stereoselectively prepared for the first time, allowing the determination of its absolute configuration as (R). The pivotal intermediate in the synthesis, 1-benzyl-4-[(S)-2,2-dimethyl-1,3-dioxolan-4-yl]-pyrrolidin-2-one 6, was previously obtained in 60% yield and 90% ee from an enoate derived from d-mannitol. Two approaches were investigated to synthesize (R)-(-)-nebracetam 1 and analogues 4 and 5 from 6. Compound 6 was transformed into WEB-1868 2. Mesylation of the hydroxyl group in 2, followed by nucleophilic substitution with azide and reduction led to target 1. Compounds 4 and 5 were synthesized by using morpholine and N-methyl piperazine as nucleophiles. Compounds 4 and 5 were also prepared, in higher yields and similar ee, through the reductive amination of aldehyde 10, obtained in two steps from 6.
